Floating roof for a tank

ABSTRACT

There is disclosed a floating roof comprising a mechanism for forcing a guiding shoe against the inner surface of a tank wall, a gutter at the lower part of the peripheral wall of the floating roof, and a flexible sealing strip connected to the peripheral wall of the gutter and to the guiding shoe.

United States Patent [72] Inventors Martinus Van der Heijden Voorburg; Tennis H. De Bruijn. The Hague: Johannes De Wit, The Hague. all of. Netherlands [2] Appl. No. 822,230

[ 22] Filed May 6, I969 451 Patented July 27, 1971 [73] Assignee Shell 0i Company New York, N.Y.

[32] Priority May 9, 1968 [33] Germany [54] FLOATING ROOF FOR A TANK 13 Claims, 4 Drawing Figs.

[52] U.S.Cl. 220/26 S [51] Int. CL. ...B65d 87/18 [50] Field of Search 220/26 S, 26, 26 D, 26 SI 56] References Cited UNITED STATES PATENTS 1,693,468 1 1/1928 Schumann 220/26 8 Maker 1,831,020 11 1931 220/26 s l,870,3l6 8 1932 Santos 220/26 s ux 1,910,922 5/1933 111115611 220/26 s x 2,542,444 2 1951 w1111111 220/26 s 2,696,930 12/1954 MOyel 220/26 5 2,754,026 7 1956 Wiggins.... 220 26 s 2,888,161 5 1959 Springer 220 26 s 2,987,215 6 1961 1661 220 26 s FOREIGN PATENTS 1,273,719 9 1961 France 220/26 s 325,954 4/1935 Italy 220/26 5 Primary Examiner-Joseph R. Leclair Assistant Examiner-James R. Garrett Attorneys-Preling E. Baker and J H. McCarthy ABSTRACT: There is disclosed a floating roof comprising a mechanism for forcing a guiding shoe against the inner surface of a tank wall, a gutter at the lower part of the peripheral wall of the floating roof, and a flexible sealing strip connected to the peripheral wall of the gutter and to the guiding shoe.

FIG. I

PATENTEflJuLemn 3,595,432

sum 2 0r 4 FIG. 2

PATENTEU JUL 27 Ian- SHEET 3 BF 4 FIG. 3

PATENTEnJuLz'nsn 3.595432 SHEEI u 0F 4 FIG. 4

FLOATING ROOF FOR A TANK at its periphery with guiding shoes adapted to slidably contact the inner surface of the tank wall.

It is an object of the invention to provide a floating roof of the above-mentioned type having the advantage firstly. that the guiding shoes, the mechanism for forcing the guiding shoesagainst the inner surfaces of the tank wall, and the sealing means, allow easy assembly and inspection, and secondly that the mechanism for forcing the guiding shoes against the inner surface of the tank wall cannot contact the liquid or vapor stored in the tank.

Therefore, the floating roof according to the invention comprises a mechanism for forcing a guiding shoe against the inner surface of a tank wall, av gutter at the lower part of the peripheral wall of the floating roof,,and a flexible sealing strip connected to the peripheral wall of the gutter and to the guiding shoe. i In a suitable embodiment the said floating roof is further characterized in that the mechanism for forcing the guiding shoes against the inner surface of the tank wall comprises a first bar of which one end is rotatably connected to the upper part of the guiding shoe and the other end is rotatably and slidably connected to the lower part of the peripheral wall of the floating roof, a second bar of which one end is rotatably connected to the upper part of the peripheral wall of the floating roof and the other end is rotatably connected to the first bar, and a spring of which the first end is connected to that end of the first bar which is rotatably and slidably connected to the peripheral wall of the floating roof, the second end of the spring being connected to the peripheral wall of the floating roof.

A further attractive embodiment of the floating roof according to the invention, is particularly suitable for use in tanks, wherein the distance between the tank wall and the peripheral wall of the floating roof has to be relatively large. Such a relatively large distance has to be present in tanks which are not purely cylindrical. This may be caused for example, by limitations in the precision achieved during construction or by distortion during a settling of the foundation.

For this purpose said embodiment is according to the invention characterized in that the lower part of the said first bar is curved away from the peripheral wall of the gutter, wherein preferably the first end of the spring is connected to the end of the first bar via an arm which is rigidly secured to the first bar.

The invention willfbe further explained with reference to the drawings, wherein:

FIG. 1 is a side view of a vertical crosssection ofa fragment of an embodiment of the floating roof of the invention adjacent to the tank wall;

FIG. 2 is a side view similar to that shown in FIG. I, but disclosing a vapor outlet forthe vapor space present below the flexible sealing strip; a

FIG. 3 is a side view of a vertical cross section ofa fragment of the floating roof of a modified embodiment of the invention;

FIG. 4 is a side view of still another modified embodiment of the present invention.

The tank wall is designated by the numeral 1 and the floating roof, which is of the usual box-shape, by the numeral 2. A guiding shoe 3 is pressed against the inner surface of the tank wall 1 by a mechanism comprising a first bar 5 and a second bar 6. One end of the bar 5 is rotatably connected to the upper part of the guiding shoe 3, by means of a pivotal connection indicated by the numeral 9. The outer end of the bar 5 is rotatably or pivotally connected to the roof 2 so as to be capable of sliding in a vertical direction. The relevant pivotal connection is free to move in a vertical direction owing to the presence of a guide 11. The center of the bar 5 is provided with a pivot pin 12 to which the bar 6 is rotatably connected. The bar 6 is preferably half, or about half, the length of the bar 5. The bar 6 is rotatably connected to the upper part of the peripheral wall 16 of the roof 2. The extension of the bottom periphery of the floating roof 2 by means of the pivotal connection 13. A tension spring 7 is connected with one end to the bar 5 at 10 and with its other end to the upper partof the periphery ofthe floating roof 2 at 13.

The bottom 14 of the roof 2 extends radially beyond the 14 is indicated by the numeral 17; the end of the extension 17 being provided with a vertical wall l8, In this way a gutter 20 is formed by the parts I6, 17 and I8. This gutter 20 is preferably so dimensioned that workni'en are able to walk along it and carry out assembly, inspection or maintenance work. i

A flexible rubber sealing strip 21 is connected to the end of the wall 18 and is further connected to the guiding shoe 3 so as to form a gastight seal. This strip 21 is spaced from the level 22 of the liquid in the tank, so that a small vapor space 23 is formed.

The ingress of rain into the space 30 between the tank wall I and the roof2 is prevented by the provision ofa weather plate 25, which on the one hand rests freely on the top surface of the roof 2 and on the other is connected to the guiding shoe 3 by a hinge, which is in the form of a strip of flexible material 26, for example of rubber. A tensioning screw 28 is operatively connected at the top end of the spring 7 in order to tension the spring 7 properly.

At the bottom of the roof 2 a stop member 27 is present.

In FIG. 2 corresponding parts are indicated by the same reference numbers as in FIG. I. The embodiment of FIG. 2 differs from FIG. I mainly by the arrangement ofa vapor outlet 29 for venting vapor from the vapor space 23 to the atmosphere. This vapor outlet 29 is provided at its top end with a suitable cap 31 containing a conventional waterlock.

Preferably an electrical connection in the form of a flexible cable (not shown) is operatively connected between the top part of the guiding shoe and the top surface of the floating roof, having the purpose of carrying off static electricity from the floating roof.

The embodiments of the invention as shown in FIGS. 3 and 4 are particularly suitable for use in tanks, wherein the distance between the tank wall and the peripheral wall of the floating roof has to be relatively large.

In the embodiment according to FIG. 3, the tank wall is designated by 40 and the floating roof by 41. A guiding shoe 42 is pressed against the tank wall 40 by mechanism.comprising a first metal bar 43 and a second metal bar 44. One end of the first bar 43 is rotatably connected to the upper part of the guiding shoe 42, by means of a pivotal connection indicated by the numeral 48. The other end of the bar 43 is rotatably connected to the floating roof4l and to the roof4l so as to be capable of sliding in a vertical direction. The relevant pivotal connection 45 is free to move in vertical direction due to the operative engagement with a guide 46. The center of the bar 43 is provided with a pivot pin 47 to which the bar 44 is rotatably connected. The bar 44 is preferably half, or about half, the length of the bar43. The bar 44 is connected to the upper part of the periphery of the floating roof 41 by means of a pivotal connection 49. A tension spring 50 is connected with one end to the upper part of the periphery of the floating roof 41. The other end ofthe tension spring 50 is rotatably secured at 51 to the free end of an arm 52, the latter being rigidly secured to the bar 43.

The bottom 53 of the roof 41 extends radially beyond the peripheral wall 54 of the floating roof41. The extension of the bottom 53 is indicated by the numeral 55. A vertical wall 56 is secured to the end of the extension 55, so that gutter 57 is formed by the parts 54, 55, 56. This gutter 57 is preferably so dimensioned that workmen are able to walk along it and carry out assembly, inspection or maintenance work. A sealing strip 58 of a suitable flexible material, such as for example rubber, is connected to the end of the wall 56 and is further connected to the guiding shoe 42 so as to form a gastight seal. The sealing strip 58 is spaced from the level 59 of the liquid in the tank, so that a small vapor space 60 is formed.

The ingress of rain into the space 61 between the tank wall 40 and the floating roof 4] is prevented by the provision of a weather plate 62. This weather plate 62 rests freely on the top surface of the roof 41 and is connected to the guiding shoe 42 by a hinge, which is in the form of a strip of flexible material 63, for example of rubber. A chain-dotted line 64 indicates the imaginary connection between the pivots 45 and 48. As clearly shown in the drawing, the lower part of the bar 43, which is indicated by the numeral 65, is slightly curved. This feature, together with the arm 52 to which the spring 50 is secured, as indicated, makes this embodiment very suitable for use with floating roofs and tanks whereby the distance between the tank wall and the peripheral wall of the roof has to be relatively large. Such a large distance is necessary when relatively large defonnations of the tank wall can be expected during use of the tank.

The embodiment of the invention according to FIG. 4 is largely similar to the embodiment according to FIG. 3. Consequently. the same elements are indicated by the same reference numerals as in FIG. 3. The difference of the embodimeht according to FIG. 4 as compared with that according to FIG. 3, is that the tension spring is differently arranged. At the free end 70 of an arm 71, rigidly secured to the bar 43, one end of tension spring 72 is rotatably secured. The other end of the tension spring 72 is rotatably secured at 73 to the lower part of the peripheral wall 54 of the floating roof 4!. The embodiment according to H0. 4 is, just like the embodiment according to FIG. 3, particularly suitable for use in tanks whereby the distance between the tank wall and the peripheral wall of the floating roof has to be relatively large.

We claim:

l. A floating roof for a tank provided at its periphery with guiding shoes adapted to slidably contact the inner surface of the tank wall, comprising:

a gutter carried by the lower the floating roof;

a flexible sealing strip connected to the peripheral wall of the gutter and to the guiding shoe;

a mechanism for forcing the guiding shoes against the inner surface of the tank wall including a first bar having one end rotatably connected to the upper part of the guiding shoe and the other end rotatably and slidably connected to the lower part of the peripheral wall of the floating roof, the lower part of the first bar being curved away from the peripheral wall of the gutter;

a second bar having one end rotatably connected to the upper part of the peripheral wall of the floating roof and the other end rotatably connected to the first bar; and,

a spring having a first end connected to that end of the first bar which is rotatably and slidably connected to the peripheral wall of the floating roof and a second end connected to the peripheral wall of the floating roof.

2. The floating roof as claimed in claim 1 including a vapor space provided below the flexible sealing strip and said vapor space is provided with a vapor outlet which comprises a tube passing through the floating roof to the atmosphere.

part of the peripheral wall of 3. The floating roof as claimed in claim 1 wherein an electrical connection in the form of a flexible cable is provided between the top part of the guiding shoe and the top surface of the floating roof.

4. The floating roof as claimed in claim I, wherein the first end of the spring is connected to the end of the first bar via an arm which is rigidly secured to the first bar.

5. The floating roofas claimed in claim 4, wherein the first end of the spring is secured to the free end of the arm.

6. The floating roof as claimed in claim 5, wherein the second end of the spring is secured to the upper part of the peripheral wall of the floating roof.

7. The floating roof as claimed in claim 5, wherein the second end of the spring is secured to the lower part of the peripheral wall of the floating roof.

8. The floating roof as claimed in claim 7, wherein the spring is provided at one end with a screw for tensioning the 9. he floating roof as claimed in claim I, wherein the space present between the peripheral wall of the floating roof and the tank wall is closed by a metal plate connected to the guiding shoe by a hinge and freely resting on the top surface of the floating roof.

10. The floating roof as claimed in claim 9, wherein the hinge is formed by a strip of a flexible material.

11. The floating roof as claimed in claim 10, including a vapor space below the flexible sealing strip and said vapor space is provided with a vapor outlet which comprises a tube passing through the floating roof to the atmosphere.

12. A floating roof for a tank provided at its periphery with guiding shoes adapted to slidably contact the inner surface of the tank wall, comprising:

a gutter carried by the lower the floating roof;

a flexible sealing strip connected to the peripheral wall of the gutter and to the guiding shoe;

a mechanism for forcing the guiding shoes against the inner surface of the tank wall including a first bar having one end rotatably connected to the upper part of the guiding shoe and the other end rotatably and slidably connected to the lower part of the peripheral wall of the floating roof;

a second bar having one end rotatably connected to the upper part of the peripheral wall of the floating roof and the other end rotatably connected to the first bar;

a spring having a first end connected to that end of the first bar which is rotatably and slidably connected to the peripheral wall of the floating roof and a second end connected to the peripheral wall of the floating roof; and

a screw means disposed at one end of said spring for tensioning of said spring.

13. The floating roof as claimed in claim 12, wherein the space present between the peripheral wall of the floating roof and the tank wall is closed by a metal plate connected to the guiding shoe by a hinge and freely resting on the top surface of the floating roof.

part of the peripheral wall of 

1. A floating roof for a tank provided at its periphery with guiding shoes adapted to slidably contact the inner surface of the tank wall, comprising: a gutter carried by the lower part of the peripheral wall of the floating roof; a flexible sealing strip connected to the peripheral wall of the gutter and to the guiding shoe; a mechanism for forcing the guiding shoes against the inner surface of the tank wall including a first bar having one end rotatably connected to the upper part of the guiding shoe and the other end rotatably and slidably connected to the lower part of the peripheral wall of the floating roof, the lower part of the first bar being curvEd away from the peripheral wall of the gutter; a second bar having one end rotatably connected to the upper part of the peripheral wall of the floating roof and the other end rotatably connected to the first bar; and, a spring having a first end connected to that end of the first bar which is rotatably and slidably connected to the peripheral wall of the floating roof and a second end connected to the peripheral wall of the floating roof.
 2. The floating roof as claimed in claim 1 including a vapor space provided below the flexible sealing strip and said vapor space is provided with a vapor outlet which comprises a tube passing through the floating roof to the atmosphere.
 3. The floating roof as claimed in claim 1 wherein an electrical connection in the form of a flexible cable is provided between the top part of the guiding shoe and the top surface of the floating roof.
 4. The floating roof as claimed in claim 1, wherein the first end of the spring is connected to the end of the first bar via an arm which is rigidly secured to the first bar.
 5. The floating roof as claimed in claim 4, wherein the first end of the spring is secured to the free end of the arm.
 6. The floating roof as claimed in claim 5, wherein the second end of the spring is secured to the upper part of the peripheral wall of the floating roof.
 7. The floating roof as claimed in claim 5, wherein the second end of the spring is secured to the lower part of the peripheral wall of the floating roof.
 8. The floating roof as claimed in claim 7, wherein the spring is provided at one end with a screw for tensioning the spring.
 9. The floating roof as claimed in claim 1, wherein the space present between the peripheral wall of the floating roof and the tank wall is closed by a metal plate connected to the guiding shoe by a hinge and freely resting on the top surface of the floating roof.
 10. The floating roof as claimed in claim 9, wherein the hinge is formed by a strip of a flexible material.
 11. The floating roof as claimed in claim 10, including a vapor space below the flexible sealing strip and said vapor space is provided with a vapor outlet which comprises a tube passing through the floating roof to the atmosphere.
 12. A floating roof for a tank provided at its periphery with guiding shoes adapted to slidably contact the inner surface of the tank wall, comprising: a gutter carried by the lower part of the peripheral wall of the floating roof; a flexible sealing strip connected to the peripheral wall of the gutter and to the guiding shoe; a mechanism for forcing the guiding shoes against the inner surface of the tank wall including a first bar having one end rotatably connected to the upper part of the guiding shoe and the other end rotatably and slidably connected to the lower part of the peripheral wall of the floating roof; a second bar having one end rotatably connected to the upper part of the peripheral wall of the floating roof and the other end rotatably connected to the first bar; a spring having a first end connected to that end of the first bar which is rotatably and slidably connected to the peripheral wall of the floating roof and a second end connected to the peripheral wall of the floating roof; and a screw means disposed at one end of said spring for tensioning of said spring.
 13. The floating roof as claimed in claim 12, wherein the space present between the peripheral wall of the floating roof and the tank wall is closed by a metal plate connected to the guiding shoe by a hinge and freely resting on the top surface of the floating roof. 